Soft solder contacts for integrated circuits - chips coated with aluminium, then electroless nickel plated and solder-dipped

摘要

At least part of one surface of a slice is coated with (a) a layer of Al, pref. 6 mu thick, then (b) nickel, pref. contg. 1-10 wt. % Cu and 1 mu thick by electroless plating; and (c) a low m.pt. solder pref. 50 mu thick by solder-dipper. The advantages are a lower saturation voltage, lower heat losses, and a higher surge current tolerance due to the heat-capacity of the lead in the solder; furthermore the process can be standardised and automated.